Method and apparatus for making inner tubes for tires



H. E. WANER June z3, 1936.

METHOD AND APPARATUS FOR MAKING INNER TUBES FOR TIRES Filed July 25,` 1955 2 Sheets-Sheet l awk huN .Je 23, 1936. H. E. WANER 2,044,961

METHOD AND APPARATUS FOR MAKING vINNER-TUBES FOR TIRES Filed July 25, `1935 2 sheets-sheet 2 unnn,

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Y JIT/522271? md.. A Y K Patented June 23, 1936 j l UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR MAKING INNER TUBES FOR TIRES Harry E. Waner, Akron, Ohio, assignor to The B. F. Goodrich Company, New York, N. Y., a corporation of New York Application July 25, 1935, Serial No. 33,003

8 Claims. (Cl. 18-14) This invention relates to procedure and apparaface with a recess I5, Fig. 2, for adjustably accomtus for making inner tubes for tires and its chief modating, with a close sliding fit, a pair of dieobject is to provide conveniently and economically aperture defining plates I6, Il, and a face-plate for producing an inner tube having a relatively i6 is secured to the nozzle by screws I9, I9 for thick wall in a localized region thereof for the retaining the plates I6, I'I in place.

purpose of counterbalancing unbalanced weight The plates I6, Il are rabbeted at I6a Ila to proin a tire casing with which the tube is assembled vide slidably overlapping portions of a combined in a wheel and tire assembly. thickness equal to that of the other portions of Prior to my invention a tube having a relatively the individual plates and the plates are provided l thick wall in a part thereof has been provided for with respective stems 2l), 2| extending beyond the 10 the same purpose, as claimed in an application peripheries of the face plate I8 for sliding the of Earl H. Barder and Clarence E. Snyder led plates I6, Il' from and toward the mandrel, 22, concurrently herewith, but, except as claimed in of the extruding machine, for varying the shape the said application, I am the originator of the of the die aperture defined by the plates I6, I1

l procedure and apparatus described therein and in and the mandrel 22. 15 the present specication. To provide for disposal of stock passing through Of the accompanying drawings: the leak spaces defined by the overlapped por- Fig. 1 is a side elevation of apparatus embodytiens of the plates I6, I1, the nozzle I4 is formed ing and adapted to carry out my invention in its in its end face with a pair of channels 23, 23 preferred form, with parts broken away. (Fig. 2) through which the stock can escape to 20 Fig. 2 is a section on line 2-2 of Fig. 1. the exterior of the device, binding of the plates I6, Fig. 3 is an elevation, with parts sectioned and Il by stock entering the leak spaces and becombroken away, of a valve mechanism constituting ingr partially vulcanized being thereby avoided. a part of the apparatus. For sliding the plates I6, Il, or for sliding one Fig. 4 is a section on line 4-4 of Fig. 2. or the other of them, their stems 20, 2I are hinged 25 Fig. 5 is an elevation, with a part sectioned and at 24, 25 to respective levers 26, 2l which are broken away, of an inner tube produced by the fulcrumed at 28, 29 to brackets or ears formed practice of my invention. on the face plate I8 and the outer ends of the Fig. 6 is an elevation of parts of apparatus emlevers are connected by a link assembly comprisbodying and adapted for the practice of my ining a two-way-acting cylinder 30 hinged at 3| to 30 vention in a modified form. one of the levers and having its piston rod 32 Fig. 7 is a section on line 'I--l of Fig. 6. hinged at 33 to the other lever, the cylinder being Fig. 8 is a section on line 8--8 of Fig. '7. provided with inlet-outlet pipes 34, 35.

Referring to the drawings, the preferred form It is preferred to form the tube with a relatively of apparatus shown in Figs. 1 to 4 comprises an thick wall zone only in outer or tread portion and 35 extruding machine Ill adapted to extrude a confor this reason the upper lever 26 is shown in tinuous tube II of rubber composition. Fig. 2 as being held in fixed position between set The finished inner tube I2, Fig. 5, has a relascrews 36, 3l mounted in the respective forks of a tively thick zone I3 in its wall, preferably in its forked bracket 38 formed integrally with the face tread region for the maximum counterbalancing plate I8, so that the upper plate I6 remains at a 40 effect for a given amount of extra stock, and for fixed distance from and concentric with the manproviding a succession of such relatively thick drel 22 and therewith denes ahalf-circular space zones in the continuous tube II as it is formed of a radial dimension corresponding to the genby the extruding machine, at such intervals that eral wall thickness of the tube to be produced,

a thickened zone will be provided in the Vicinity whereas the lower lever 2l extends with sub- 45 of the valve stem in a succession of inner tubes stantial play between a pair of set-screws 39, 40 made from lengths of stock cut from the continmounted in the respective forks of a forked uous tube II the extruding machine is provided bracket 4I formed integrally with the face plate with a special head having means defining a die I8, the upper set screw 39 of the pair being set aperture of variable shape and means is provided at such position that the lower aperture-defining 50 for periodically changing the shape of the die plate I1 will be in concentric relation to the manaperture, drel 22 and at the same distance therefrom as the The said head comprises a nozzle I4 threaded upper plate I6 when the upper end of the cylinder into the cylinder of the extruding machine, as 30 is charged to lift the lever 21 into contact shown clearly in Fig. 4, andfforrned in its outer with the set-screw 39, and will be in a lower, 55

eccentric position corresponding to thickness desired in the relatively thick, counterbalancing zone of the tube when the lever 21 is forced against the lower set-screw iii by charging of the lower end of the cylinder 36.

For alternately charging the upper and lower ends of the cylinder 3e and venting the other end in proper timed relation to the advance of the extruded tube ll the inlet-outlet pipes Sli, 35i are connected to respective pipes Q2, i3 which are associated with a control-valve assembly ill having a supply pipe i5 and a vent pipe 46.

The valve assembly comprises a casing formed with an upper chamber l (Fig. 3) which is in constant communication with the supply pipe [l5 through a port lie. Mounted between the floor of said chamber and the base of the casing are a pair of tubular valve members 49, 5i), each formed with a partition 5l, 52, near its middle.

The upper end of the member t9 is in constant communication with the chamber el' through a port 53 and the upper end of the member 5i) is in constant communication with the chamber ll through a port 5d.

The member i9 is formed with a set of apertures such as the aperture 55 through its side wall above the partition and with a set of apertures such as the aperture 5b through its side wall below the partition, and the member 59 is likewise formed with sets of apertures such as the apertures 5l and 58.

Slidably mounted upon the member i9 is an internally recessed ring 59 adapted when in its upper position to shut off communication between the apertures 55 and 56, and to allow communication of the upperrend of the cylinder 3@ with the exhaust or vent pipe LES, through the aperture 2lb, and, when in its lower position, to shut 01T the communication with the exhaust and providecomn'lunication between the supply pipe i5 and the upper end of the cylinder B.

A ring es like the ring 59 is provided upon the tubular valve member 5e and is adapted to function in the same manner for charging and venting the lower end of the cylinder.

' The rings 59 and 6% are provided with respective yokes having stems 8i, S2 slidably mounted in and extending to the exterior of the casing and for simultaneously moving the rings in opposite directions'the upper ends of the stems are hinged at 63, 64 to the respective arms of a lever B5 which is'hinged at its middle to a bracket 5S formed on the top of 'the casing.

The outer ends of the lever 55 have link connection to the cores of respective solenoids 6l, 61a which are in respective electric circuits 58, 69 controlled by a mercury switch 'lll mounted upon a standard 'il which rises from the frame of a conveyor l2 adapted to convey the continuous tube I from the extruding machine.

A pair of levers 13, lll are pivoted at 'l5 on the standard 'il for tilting the mercury switch in one direction and then the other, the lever 73 having a rearward extension 13a adapted to be contacted by a dog 16e on a measuring wheel i6 rotatably resting upon the tube, for actuating the lever, and the lever 'M having connection through a link 11 with a lever i3 pivotedy at 79 on the standard and having a rearward extension Sil adapted to be contacted by the dog 'ita for actuating the lever lll, the levers 13 and la being adapted to be returned to their lowermost positions by gravity, against respective stops 8|, 82 as the dog la passes out of contact with the lever extensions 13a, 80.

It is believed that the operation of the app-aratus will be entirely clear from the foregoing, the lower die-aperture plate Il being periodically lowered for a time corresponding to the movement of the dog '16a from the lever extension I3a to the lever extension 88, to provide the successive thick zones in the continuous tube at intervals corresponding to the length thereof representing a iinished inner tube.

The continuous tube preferably is subsequently severed into lengths at such positions that the valve stem can conveniently be mounted in the wall of each length at a position cross-sectionally opposite to the relatively thick zone, and before or after the valve stem is so mounted the ends of the length are spliced together and the resulting endless tube is vulcanized in a mold under internal fluid pressure or in any other known or preferreol way.

The above stated object is thus conveniently and economically attained.

In the modiiication shown in Figs. 7 and 8 the extruding machine is of the side-delivery type and a shutter similar to a camera shutter and comprising an outer circumferential series of overlapped plates 83, 83 and an inner circumferential series of overlapped plates im, 84 are provided for dening and varying the size of the die aperture.

The plates of the outer series are slidably held in position between the casing B5 of the extruding machine nozzle and an annular member 86 secured to the casing by screws 8l, 8l, and the plates of the inner series are slidably held in position between an internal, central arm 88, formed integrally with the casing, and a cup-shaped member 89 secured upon a reduced extension of the arm by a nut Q9.

For radially adjusting the plates of the outer series they have dove-tail connection at their outer ends with the generally conical inner wall of an annular cam member 9i slidably mounted upon the annular member S6 and adapted to be adjusted axially of the nozzle by a ring 92 threaded upon the casing 85, the ring 92 being internally formed with an annular groove in which are slidably mounted the outer ends of pins 93, 93 projecting from the annular cam member 9| through axially disposed slots Sil, 94 formed in the casing of the nozzle.

For radially adjusting the plates of the inner series they have dove-tail connection at their inner ends with th-e generally conical outer wall of a cam member 95 slidably mounted on the reduced extension of the arm 88 and adapted to be adjusted axially of the nozzle by slide bars 95, 96 extending through longitudinal holes in the arm and connecting the cam member $55 with a disc S1 having its margin mounted in an inner annular groove defined by an annular two-part screwplug 98 mounted in a threaded socket formed m the casing 85.

The apparatus of this modication is adapted for forming tubes of different cross-sectional diameters or for forming a continuous tube of varying wall thickness for counterbalancing purposes as above discussed, the ring 92 and the screw-plug 98 being formed to receive suitable spanner wrenches for turning them.

I claim:

1. Apparatus for making inner tubes for tires, said apparatus comprising an extruding die adapted to form a continuous tube of uniform cross-section, and means for adjusting the die 75 during the extrusion of said tube to change the wall thickness of the tube around a portion of its circumference.

2. Apparatus for making inner tubes for tires, said apparatus comprising an extruding die adapted to form a continuous tube of uniform cross-section, and means for automaticallyv adjusting the die to change the Wall thickness of the tube around a portion of its circumference.

3. Apparatus for making inner tubes for tires, said apparatus comprising an extruding die adapted to form a continuous tube of uniform cross-section, and means controlled by the eX- truded tube for automatically adjusting the die during extrusion of the tube to change the crosssectional area of the tube.

4. Apparatus for making inner tubes for tires, said apparatus comprising an extruding die adapted to form a continuous tube of uniform cross-section, and means controlled by the extruded tube for automatically adjusting the die during the extrusion of the tube to change its Wall thickness around a portion of its circumference.

5. Apparatus for making inner tubes for tires, said apparatus comprising an extruding die formed of a plurality of die elements defining an extruding orifice adapted to form a continuous tube, and means located in the path of the tube and actuated thereby for periodically adjusting said elements to form successive thickened portions of the tube wall. 5

tube, and means located in the path of the tube 10 and actuated thereby for periodically adjusting said elements to form successive thickened portions along a portion of the circumference of the tube.

'7. The method of making an inner tube which 15 comprises continuously extruding a rubber tube from an adjustable die, and intermittently adjustine' the die to form thickened portions extending around part of the circumference of the tube.

8. The method of making an inner tube which 20 comprises continuously extruding a rubber tube from an adjustable die, and adjusting the die during the extruding of the tube to determinately change the wall thickness of the tube throughout a partA of its circumference. 25

HARRY E. WANER. 

